1. Field of the Invention
The present invention relates to an electronic blackboard system and more specifically to an electronic blackboard system adapted to provide a hardcopy of the information written on such information writing boards as white boards, blackboards or the like.
2. Description of the Prior Art
FIG. 1 is a front view showing a conventional electronic blackboard system as previously proposed by, for example, the applicant of the present invention. FIG. 2 is a side view of the electronic blackboard system shown in FIG. 1. FIG. 3 is a block diagram showing the flow of signals in the electronic blackboard system shown in FIG. 1. In the respective drawings, numeral 1 denotes a board on which information can be written, numeral 2 denotes a guide rail attached to said information writing board 1 in such a manner as to be parallel to the upper edge thereof, numeral 3 designates a photoelectric conversion device (a photoelectric device) having a CCD (charge coupled device) image sensor longitudinally formed therein, a light receiving part being arranged on the front face of the imagesensor and LED (light emitting diodes) being arranged side by side at the side of the light receiving part, numeral 4 designates driver means respectively attached at the opposite ends of said photoelectric device 3 and adapted to move said photoelectric device, 3 leftwardly and rightwardly in synchronism with each other, numeral 5 designates a position detector comprising a light source (LED) and a photosensor facing each other and adapted to detect the presence therebetween of any of the tongue pieces or strips 2a which are provided at the opposite ends of said guide rail 2, numeral 6 designates a cable for signals which is connected to the power source (not shown), numeral 7 designates a buffer memory adapted to store the information images derived from the photoelectric device 3, numeral 8 designates a device for producing a hardcopy, such as a printer or the like, and numeral 9 designates a stand provided with a lateral frame (a supporting portion) 9a for the information writing board 1, the guide rail 2, the buffer memory 7 and the hardcopying device 8 and a guide rail part 9b adapted to guide the lower end of the drive device 4 and capable of stably supporting the entire blackboard device on a floor.
Next, operation of the blackboard device according to a prior art as shown in FIG. 1 through FIG. 3 will be explained. In the blackboard system constructed as above mentioned, the photoelectric device 3 employed is of such a type that the light receiving part and LED are slightly spaced apart from the information input face, or of the so-called closely contacting type wherein the information written on the information writing board 1 is read in terms of longitudinal lines and converted into electrical signals. Said photoelectric device 3 is caused to move leftwardly or rightwardly at a constant speed by means of the drive device 4 and to stop at certain positions so as to enable said position detector 5 to detect the presence of said tongue pieces 2a or at the positions at the left end or the right end of the information writing board 1. In this way, when the photoelectric detector 3 has been displaced to the right end from the left end of the information writing board 1 or from the left end to the right end thereof, an information image on the blackboard is obtained by means of the CCD image sensor constituting the photoelectric device 3 and this information image may be recorded by the hardcopying device 8 after being stored in the buffer memory.